Packages



Jan. 8, 1963 J. w. HARRISON 3,071,819

' PACKAGES Filed Jan. 3, 1961 INVENTOR JOH N W. HARRISON ATTORNEYS United States necticut Filed Jan. 3, 1961, Ser. No. 80,308

3 Claims. (Cl. 18-59) This application is a continuation-in-part of application Serial No. 777,785, filed December 2, 1958, now abandoned.

, This invention relates to novel packages. More specifically, it relates to packages such as book covers and wallets.

Book covers which are conventionally employed today are generally opaque and it requires considerable time to apply the cover to the book. Additionally, the book covers are formedby the laborious process of folding a blank of paper and then gluing the paper in appropriate places to form the envelopes into which the front and back covers are inserted.

It is an object of the present invention to design an improved book cover.

Another object is to prepare a book cover which can be shrunk tightly around the book to give a neat appearance.

A further object is to provide a book cover which can be quickly applied to the book.

A still further object is to provide novel packages from irradiated, biaxially oriented polyethylene.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

The invention will be better understood in connection with the accompanying drawings wherein:

FIGURE 1 is a top plan view of the book cover;

FIGURE 2 is a sectional view on the line 2-2 of FIGURE 1;

FIGURE 3 is a sectional view on the line 33 of FIGURE 1;

FIGURE 4 is a perspective view illustrating the insertion of a book in the cover;

FIGURE 5 is a perspective view illustrating the book already inserted in the cover prior to shrinking the latter;

FIGURE 6 is a vertical elevation, partially in section, illustrating the manner of shrinking the cover.

The objects set forth above are accomplished according. to the invention by utilizing an irradiated, biaxially oriented polyethylene. In the illustrative examples, there was employed Alathon 14 (polyethylene, molecular weight about 20,000, density 0.916) which had been irradiated to an extent of 12 megarads and had then been stretched 350% longitudinally and 350% laterally and had a shrink energy of 250 p.s.i. at 96 C.

The book covers of the present invention have the advantage over conventional covers of being more abrasion resistant and also of .having greater chemical and heat resistance. Furthermore, the polyethylene tubing or film employed is clear and normally colorless. Additionally, by utilizing the heat shrinkable films or tubing according to the invention, it is possible to have one jacket fit several book sizes tightly. Furthermore, the form of the jacket is very economical on film requirements and places a double thickness across the back of the book where severe strain commonly occurs.

Referring more specifically to FIGURES l-6 of the drawings, there is provided a book cover or jacket 2 made of the irradiated, biaxially oriented polyethylene. The cover for a book 4 of given dimensions is made from tubing or film having a flattened width B somewhat larger than the corresponding width B of the book. Preferably, the width of the cover is 5 to 25% larger than that of the book. The edges 6 of the cover are folds if tubing is used and are heat seals between two layers of film in the event that sheet film is employed to form the cover. The edges 8 and 9 are heat seals when either tubing or film is employed. The inner layer 14 of film or the inner layer of tubing is slit as indicated at 10 and 12, while the outer layer 16 is not slit. The slits 10 and 12 are made before end seals 8 and 9 are formed by inserting a plate to out against. The A, C and D dimensions which together are the length of the cover can also be larger than the corresponding dimensions of the book by from 5 to 25%. Preferably, however, the D dimension of the cover is nearly equal to the corresponding dimension of the book.

T o fit the cover 2 to a book, the cover panels 20 and 22 of the book are folded back to be nearly parallel and inserted simultaneously through the slits 10 and 12, as shown in FIGURE 4. The cover 2 will be somewhat larger than the book 4 as shown in FIGURE 5. The film or tubing is then shrunk with hot air from heater 24 to bring the film down evenly. Care should be taken not to draw the edges of the film or tubing back along the D dimension to expose the binding. Preferential shrinking of the insides of the cover panel envelopes 26 and 28 and the outside edges along the D dimension aid in forming an evenly applied finished cover.

In the event that a double thickness of film over the back is not desired when utilizing film rather than tubing to form the cover, then a single layer of film is employed. The end seals 8 and 9 in this embodiment are in the form of folds and the ends of the film are laid back for the distances A and C. Edges 6 are heat sealed for the distance A and C and the center along D' is a single thickness of film. Preferably, however, D is of double thickness as shown in the drawings.

While the drawings illustrate the covering of a hardback book, the invention is also suitable for preparing covers for magazines, soft-back books, pamphlets, etc.

In general, there is employed in the invention polyethylene film or tubing which has been irradiated to an extent of 2 to megarads, preferably 6 to 20 megarads. The irradiation can be accomplished in conventional fashion, e.g., by the use of a high voltage resonant transformer, such as the 2,000,000 volt General Electric resonant transformer, or high energy particle generators of 50,000 to 50,000,000 volts or a Van de Graaff electron generator. In addition to the use of electrons, there can be employed beta rays, gamma rays, e.g., by employing cobalt 60, etc. There can be employed any of the irradiation procedures disclosed in Baird application Serial No. 713,848, filed February 7, 1958, now Patent 3,022,543, for example. The entire disclosure of the Baird application is hereby incorporated by reference.

The biaxial orientation is normally carried out to an extent of 100 to 700% longitudinally and 100 to 900% laterally. The biaxial stretching can be carried out by blowing irradiated polyethylene tubing as disclosed in the Baird application. The irradiated, biaxially oriented polyethylene prepared by such a procedure has a high shrink energy, e.g. 100 to 500 p.s.i. at 96 C.

There can be employed as the starting polyethylene for the irradiation procedure high, low or medium density polyethylene prepared by low or high pressure technique.

Fatented Jan. 8, 1963 The starting polyethylene can have a molecular Weight of 7,000 or 12,000 or 19,000 or 21,000 or 24,000 or 35,000 or even higher.

In place of irradiated polyethylene, there can be employed similarly irradiated polypropylene.

Likewise the book cover can be made of other heat shrinkable polymers such as biaxially oriented polystyrene, biaxially oriented vinylidene chloride resin (biaXially oriented saran), biaxially oriented mylar (polyethylene terephthalate), biaxially oriented rubber hydrochloride, biaxially oriented unirradiated polypropylene, biaxially oriented unirradiated polyethylene, biaxially oriented copolymer of ethylene and propylene (irradiated or unirradiated).

The heat shrinkable biaxially oriented polymers employed as book covers are usually colorless and hence any decorative or written matter on the cover panels and backing of the book itself are visible. Alternatively permanent decorative or written matter can be applied to the polymer film book cover.

What is claimed is:

1. A method of covering a book having attached cover panels comprising inserting the book cover panels into slits in an otherwise completely closed heat shrinkable polymer cover, said cover being larger than said book and then applying heat to shrink the polymer cover to closely fit but not adhere to the outside contours of the book.

2. A method according to claim 1 wherein said polymer is biaxially oriented, irradiated polyethylene.

3. A method according to claim 1 wherein said polymer is biaxially oriented polypropylene.

References Cited in the file of this patent UNITED STATES PATENTS 2,679,969 Richter June 1, 1954 2,865,767 Gore Dec. 23, 1958 2,877,500 Rainer et a1. Mar. 7, 1959 FOREIGN PATENTS 1,041,118 France May 27, 1953 

1. A METHOD OF COVERING A BOOK HAVING ATTACHED COVER PANELS COMPRISING INSERTING THE BOOK COVER PANELS INTO SLITS IN AN OTHERWISE COMPLETELY CLOSED HEAT SHRINKABLE POLYMER COVER, SAID COVER BEING LARGER THAN SAID BOOK AND THEN APPLYING HEAT TO SHRINK THE POLYMER COVER TO CLOSELY FIT BUT NOT ADHERE TO THE OUTSIDE CONTOURS OF THE BOOK. 